(1) Field
The present disclosure generally relates to surface mount flanged pins and particularly, is directed to a method of manufacturing flanged pins in an end to end format.
(2) Description of the Related Art
Generally, surface mount pins are inserted into a work piece to act as an electrical interface between the work piece and conventional connector wiring devices. Typically, the pins are made in an end-to-end format, where coiled wire is straightened and formed into the specified pin geometry. The pin can then be separated using a pin insertion machine, which separates one pin from the end-to-end chain. The separated pin can then be positioned over the work piece and inserted by pushing a preset distance on the tip of the pin. Variables such as the speed and inertia of the insertion process, the actual size of the hole in the work piece, and the relative ability of the pin geometry to resist deflection when subjected to the insertion forces, can cause the insertion depth to vary and deformation of the pin shaft to occur. The method of making a pin for a circuit board is described in U.S. Pat. No. 4,769,907, to Sebastien, and is hereby incorporated by reference in its entirety.
In most situations the pin and work piece require a soldered connection. This is typically achieved by applying a solder paste to the conductive surface around the hole in the work piece as well as directly over the hole in the work piece. The pin is then inserted through the solder paste and into the hole in the work piece. Some of the solder paste adheres to the pin and subsequently forms a solder fillet between the pin and the conductive surface around the pin during the reflow process. However, some solder paste is dispersed by the pin as it is inserted, resulting in waste and the possibility of contaminating the work piece with free conductive material.
The use of this type of pin in a work piece has many drawbacks. Several factors, such as the force required for the insertion and the strength of the pin can lead to inserting the pin too deep or not deep enough, or, breaking or bending of the pin. In addition, the use of large amounts of solder can lead to waste and contamination.
Rather than a straight pin, as discussed above, a flanged pin can be used in a work piece. A flanged pin has a rim (i.e. a flange) around a portion of the pin. The flange provides a rigid surface for pushing the pin into the work piece and thereby eliminates the potential for distorting the pin shaft. The flange also defines a precise seating plane by preventing the pin from being inserted beyond the specified depth. Additionally, solder can be applied to the conductive material around the hole in the work piece directly beneath the flanged portion of the pin to create a 360 degree, high strength, low electrical resistance, no waste joint after the reflow process.
Flanged pins are currently more difficult and expensive to manufacture than straight pins. Typically, flanged pins today utilize turret fabrication using lathe equipment. This is a very costly manufacturing method and requires slow bowl feeding insertion equipment. What is needed is an effective way to produce a continuous reel of flanged pins.